[Jukebox-list] Audio question

[Jjmscf at aol.com]

They're useful for that on home equalizers too.In my case I like lots of bass 
but I'm limited on how far I can put my  speakers from the tuntable on my 
home system due to lack of space. The right speaker is not a problem where I 
placed it.( I think because it's far away from any corners.I could stop the 
feedback by moving the balance to the right.) but only the equalizer can stop the 
acoustical feedback at very low frequncy that no amount of isolation could from 
the left plus moving the speaker away from the corner could.I put a jukebox in 
the corner instead.The speaker kinda looks funny between a chair and the 
jukebox  while the other sits flat agains the wall on the right side of the tv but 
that's where the feed back was much lower.It was terrible when it was in the 
corner.I couldn't even get past 3 and 1/2 out of 10 on the volume before it 
started rumbling.If turned higher it would break into low frequency oscillation 
that threatened to shatter the windows in the room.It was still there slightly 
when the volume was cranked even holding the turntable in the air so the 
feedback to the cartridge was through the air. But turning the bottom most control 
on the left channel on my 9 band per channel equalizer down and  I can crank 
it to ear splitting levels with all the bass I want and no feedback.
Jukeboxes must roll off the low end  at a certain frequency to prevent this 
but most have no shortage of bass. I had to struggle to eliminate it in a home 
stereo and everything is right there in the same cabinet on a jukebox and they 
don't feedback unless you have bad isolation parts such as motor grommets in 
a Rockola,AMI or Wurlitzer and motor coupler and turntable grommets in a 
Seeburg.I do have on the home stereo those big 15" woofer speakers from the 
80s.I've tried over the years different turntables,different cartridges,room 
placement,hanging the turntable from the ceiling, you name it.Until I finally lucked 
on the right speaker placement and that little Kenwood equalizer turntable 
feedback was the bane of my existence.Or maybe my  light tracking high compliance 
cartridge just doesn't like those foam surround bass reflex woofers.The 
cartridge does claim to go down to 15 hz. Maybe that's where the feedback was being 
picked up?
 
J.C.
 
 
In a message dated 7/24/2007 5:22:45 PM Eastern Daylight Time, 
wesleydean at cox.net writes:

>One useful purpose of EQ's is the use of 'T' notch filters to eliminate 
>acoustical feedback in auditoriums. They are also good in tailoring sound 
>for defective ears on a personal level. I once had a friend that had to roll 
>off the low end at 500 hz. Wes





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